Does kissing another guy count as cheating ? ♥ ♥?

hey lolz, yeah so my bf Derek was mad at me earlier coz he found out that i kinda made out wiv this boy in a nightclub, it weren't like dirty or nufin - the guy jus said how i looked nice in this dress i woz wearin like..i mean, the last bf i had i slept wiv other guyz n he didnt mind...what you guys fink, is he bein too over the top ? xoxo