what should i do if i got my penis stuck in a sex toy and my girl comes in?

You two should have talked about your mutual sexual desires and activities long before that happens. If you two are in love and, presumably, are sexually intimate in your relationship, then you two should feel comfortable to have a very open and honest communication where you can talk about anything and everything together. Just as she should feel comfortable to tell you about her possession and usage of dildos and how she masturbates, you should feel comfortable to tell her about your possession and usage of a sex toy and how you masturbate. Not only will that eliminate any surprises if one should be in the middle of something when the other comes in, it will help you both get to know the other person, the true person, just a little bit more and help strengthen the relationship. You should both understand that use of a toy is nothing more than masturbation to satisfy an immediate need and not a reflection on the sexual quality or capabilities of the other. Definitely talk with her first so she knows you own a sex toy, and if she should ever come in while you're using it just act like it's a complete non-issue that she's seeing you in such an intimate moment. If she sees that you're completely comfortable with her seeing you in that position then she'll see you have absolutely nothing to hide from her and will likely trust you more. It may also inspire her join in.

Why would you use a sex toy expecting your girl? Troll.

Embrace the awkward moment.

Have her come to your aid in a hurry.

tell her to join you maybe you guys can laugh at it and she can help