He's really weird about muscular men and black muscular men in particular. He fixated on that athletic black guy from his highschool that "Coulda been a model" he stole the hot latina from, supposedly. If he really was on happy pills as a teenager his dick probably didn't work then. It's the age where guys might actually start getting some, so if their first attempts are terrible, I could imagine that being very discouraging. In general, Phil's pretty much linked one ED-causing condition into another flawlessly.
From happy pills in his teens, to heavy drinking to his early 30s, then gout. I'm generally one of the biggest proposers of the Phil is an actual flaming faggot theory, but to be completely fair I never meant the guy would enjoy bottoming for Kenny Omega or whatever, it's just that what little sex drive he has is mostly saved for muscular men. Or male friends. He almost always acted as a jilted lover around Rambo. He acted as a jilted lover around Brian as well, not letting him strike a conversation with Kekon. It's not like he's not surrounded by dents and degenerates. If he wanted to sext a dude, I'm sure Anonymouse, Swagginz or OIC would have been receptive. He has this weird admiration for manly men, and he considers troon porn funny and not offensive, so maybe in another life he would have actually been a flaming faggot. Not in this one though. No one has less patience for ED than gay men.
Almost every exchange he had with LTG about how he's taken care of his sexy, and LTG is a sexy man, and LTG is in great shape and takes care of himself has been really fucking odd, like Phil's got the tub of vaseline ready and is giddy at the prospect of LTG's bbc rearranging his guts. To me, the smoking gun was Phil's little happy ditty about LTG being a sexy man. I've never heard of other 30-somethings refer to other men as sexy. Handsome maybe, attractive, but never sexy. Dudes will call a car sexy before they call a man sexy. Might as well be him being an alien in a skinsuit.
He, of course, had pics of muscular black men with a boner on his top haters website. When he was interested in women he was always really dismissive of them and interested only in weird, humilliating or uncomfortable sex practices: Motorboating, girls showing stuff, anal sex. Nothing that might feel good, just "For show or to say you've done it" shit. Not just me saying this, in his tirade about fucking dweeb female cosplayers in the ass, he specifically said that it would be done as a sign of disrespect. He wrote a literal incel manifesto.
After this in the early youtube days, he of course acted like an insatiable horndog. It's not weird for closeted gay men to act like this to fake being straight, it's just weird that Phil did this. It was the late 2000s. Being gay wasn't exactly a death sentence in Connecticut. It's not like he lived in Shitholeistan. Then he just went to get a beard.
Of course, his choice in women is heavily suspicious. I think with Leanna he was just a virgin and knew next to nothing. He had read somewhere or heard from some FGC chuds that aw men, women just NEVER want to put out, so that's what he went with. Leanna was about status. He had always fronted on SRK forums that he had a hot girlfriend from Canada, but Leanna made that a reality. So he paraded his hot young nympho, obviously this heavily drinking, unhealthy, 28 year old virgin who has never been seen before with a woman was a secret Chad all along and all the naysayers can lovingly entangle the hairs on his butthole using their tongue. Or, ED-ridden, possibly closet queen man looks for what will make them appear the manliest in their environment.
Kat's just perfect. Lazy potato, on happy pills, so obviously no sex drive, gamer, shares an interest in junk food, so clearly Phil doesn't have to worry about getting it up any more. So now he can be a weird prude. But it's mostly sour grapes. Phil's so out of touch with his sexuality he probably doesn't even realize that he's what can be charitably be defined as not straight. Between his catholic upbringing, extremely weird personality Frankenstein'd from The OC and The Sopranos, weird inflections where he talks like a flaming faggot emulating a valley girl but who's ALSO from Joisey, and the likely fact that his father would disown him if he turned out to be a pole smoker, Phil's never thought of himself as anything other than straight.
His poor reactions to attractive females can be summed up as sour grapes. He's never been able to handle a woman. In his 40s, with an unhealthy lifestyle, and a sexless potato as a wife, he's not gonna start now. His reactions to attractive males are, I feel, what he truly wants, but this is 100% speculation and even if I was right
TL;DR: I think if Phil had any sex drive, he'd probably be gay, but even then he'd remain firmly in the closet. As it stands he just has no interest in sex. I don't think he ever has it. It's probably because he sucks at it, because he's going against his actual wants. But even disregarding that, he most likely can't get it up and hasn't been able to probably since he reached sexual maturity. That one strange tale he told about being at the peak of his masculinity when he was 13 implies that was the last time he even masturbated. The Incident was probably because Leanna was on the way out and tired of letting him push rope. Nah, the guy drinks too much, and has too much gout to want to park his todger anywhere, and even if it did work, he'd never have the balls to actually find himself some manbutt.