Lily: How can you be in love and still be sleeping with anything that moves?
Barney: I'm sorry, I don't follow you. That's like saying "How can an ant carry 20 times it's body weight, but root beer floats are still delicious?" Are the two even related?

Lily: You're in love? That's so sweet!
Barney: It's not sweet! It's like a disease! I slept with Robin one time, and I caught feelings. I caught feelings bad. I used protection and everything.

Lily: Barney, you're gonna have to stop screwing around if you want to be Robin's boyfriend.
Barney: Wow, wow, wow, ha, ha, boyfriend? I don't want to be Robin's boyfriend.
Lily: Well, what do you want then?
Barney: I don't know! I just want to be with her. All the time. I want to hear about her day, tell her about mine, I want to hold her hand, smell her hair. But I don't want to be her stupid boyfriend.