Well, shes not BI so I seriously doubt shes had any "experiments" with guys. If she did that would be a glaring negation of her supposedly being a queer only LI option. I doubt bioware would make such a mistake.
Err, so every real live homosexual person who has had to deal with compulsive heteronormativity, who tried dating or having sex with the opposite sex in order to be accepted by their family and community before being able to come out, they're "glaring negations" of their own sexual orientations?
It would be nice if Sera had a loving, open minded family who accepted her sexuality immediately, and never felt pressure from society to attempt to fit in by dating a guy. I'd like to hear about it in game, if that's the case. But feeling obligated to TRY to be straight does happen in real life, (even though it's obviously awkward at best and painful and horrible at worst) and it could be written in a way that isn't titillation for straight guys or feels like an after school special (kids don't have these anymore so google it).