She probably waited to text him as long as she could before giving in!

Sofia Richie celebrated her 18th birthday at The Nice Guy last night with an entourage of male pals, but rumored boyfriend Justin Bieber was nowhere in sight! In fact, he was across town at The Doheny Room, and when Lionel Richie's daughter wrapped up her evening at the celeb hotspot, she booked it over to JB's location to be by his side.

The barely legal socialite must not mind the fact that The Biebs isn't a one woman man. After all, he was just spotted with British model Bronte Blampied in London, and before that he was skinny dipping in Hawaii with Australian model Sahara Ray. Dude gets around!

Perhaps that's why Sofia was sick just a few days ago? She should think twice about making out with someone that is making out with everyone! That's how germs spread, y'all. Earlier in the afternoon, she stopped by Earth Bar to grab some vitamins to fight her flu. If they sold cheating boyfriend elixir, she'd be on the mend by now!