In my opinion, every body does that nowadays, have multiple relationship at the same time (even gals). That's the mistake everyone makes. Not trying to be rude but it was just his stupidity to not to care to wear a protection. For now, its already happened, so bro I will suggest you to confess your mistake to both of your women, and the one who truly loves you will be able to forgive you and walk with you forever.

Peace Out.......