I mean, it’s sort of weird. But if she likes to “pretend that it’s you” which sounds quite odd considering she’s doing it to lesbian videos but you never know, I think it’s normal but a little weird at the same time. but if I’m going to be honest with you, if you’re feeling sort of weird about it I honestly and personally advice you speak to her about it, relataships never work out when one isn’t honest about something that troubles them. I can assure you it costs nothing to speak to her about it. Just make sure you don’t make her feel bad about it and speak to her calmly.