I play a homosexual male character for aesthetic reasons, like I date men in the real world for aesthetic reasons. It's the same reason, also, that I would never choose a dwarf LI option and why I only play human and elven characters.
Sexuality isn't inherent to how you act towards other people. All gay, straight and bisexual people act entirely different. I really don't know in what way you think sexuality has a huge impact on personality. If this were true we'd have a set list of ways that each sexuality is able to act. Clearly we don't. Each sexuality can act any way towards anyone regardless of their sexual preference. I just can't wrap my mind around what people mean when they say this at all and I've yet to have anyone explain it with any sort of example.
So, in what way does sexuality effect your personality? I get that you think it does. How does it effect your personality?
I don't think that gay people behave like this and straight people behave like that, I'm talking about individual persons here.
Probably rather simple Example:
A Girl is straight and makes friends with several other Girls at School. They become bffs, Support each other, she can always rely on their help and will identify with her Group while looking down upon others who are different from them, because she can't relate to their problems much and is influenced by her friends a lot. She doesn't have much confidence when she's on her own and will tend to rely on other people instead of taking responsibility herself and rather back down than disagreeing with someone. She has a pretty good time at School and is happy most of the time.
The same Girl is gay in a parallel universe. She makes friends with several other Girls at School and falls in love with one of them over time and the others find out about it. People at her School are making fun of her because of it, her friend is grossed out and doesn't wnat to talk with her for a while and even her other friends now behave different towards her. She is embarassed and hurt, turns away from her group, becomes more of a loner and eventhough some of her friends and other people at her school are still on good terms with her, she will be more cautious who to trust from now on. Because she is sometimes harassed for her sexuality and being different, she identifies strongly with other minorities, doesn't let herself be influenced by the opinions of others as easily and will eventally become someone who fights for others and can stand up for herself and stand on her own if she has to, eventhough she doen't always have it easy.
In both parallel universes the Girl might be good at School, love singing and painting, have a good relationship with her family and eventually get the Job she always dreamed to have, but depending on the universe she will behave very different in certain situations.
Sorry if the example is dumb in some way and I needed super long to write this, but right now it's pretty late where I live . ^^'