If you're talking to a girl and your friend joins the conversation and then decides to throw you under the bus he's "simpin" and he is a "simp" for that, it's like accusing someone of being disloyal a sort of snitch. It's above and beyond hugging a puppy on tinder. Although people throw around simp casually on the net imo calling someone a simp is more disrespectful than calling someone a bitch.
