Cockiness is disgusting if I'm interested in a relationship with that person. Cockiness is entertaining in general but it isn't something I'd want to deal with on a daily basis if I'm dating someone.
Although, cockiness is a quick way to get laid. It's like a mating call to anyone who wants a one night stand tbh
In the bedroom, sure. It's a major turn-on when someone boasts about their body and stuff. But outside of all that, it just sounds very arrogant and annoying. Confidence is great and, in some cases, a must.. but I don't want someone who's cocky 24/7, 365.