My friend's a lesbian and I'm straight but people are starting to think I'm gay too. What do I do?

My friend told me people think we're dating. It's not that I have an issue with lesbians it's just I'd rather not have people making up rumours. I don't know what to do, I feel like I need to start acting differently.

You need to get a bf.

Assure them you're not into girls, and then ignore them.
People are always going to talk, but you don't want to fuel it.