Another very interesting Forum topic resurrected from the Forum of old...
Personally, I try to avoid "direct causal relationships" from my childhood to my adult life. I think the "3D matrix" that makes up the formula that determines who and what we're attracted to (sexually, socially, and every other way) is so complex that no 1 piece is likely responsible for "all" of it...
To wit: yes, the absence of physical love or emotion from your parents likely will impact your desire for that later in life (wanting to fill a void, so to speak)... but your choice of who to fill that void is less likely tied to that than you would think.
I have worked as a counselor (church) for many people who have had "parental love" issues... some blamed that for their sex-addiction (mostly straight, tho some gay as well)... more than a majority of those people also fantasized about sex with a parent or parent-like person. (My point is: that's not a "gay" thing, that's a "human" thing!)
For me personally, I've always been attracted to men in their 30's and 40's... when I was a teen, I was attracted to them... when I was in my 30's and 40's I was attracted to them, and now in my late 50's I'm still lusting after guys in their 30's and 40's... My first "real" boyfriend (live-in) was 12 years older than me (22-34), and my current boyfriend is 20 years younger than me (58-38)!
I certainly agree with the generalized comment that mixed-generation relationships can be fraught with challenges... but people in relationships always change! It's only human! What makes a relationship work is how you adapt together to each others' changes. I've known plenty of same-aged relationships that have failed because "they changed" and they couldn't adjust... and I've known a few x-gen relationships that have lasted decades - because as they changed, they adjusted and accepted each other. IMHO, that's what LOVE is!