撩妹杠把子
[liáo mèi gāng bă zi]
In a humorous manner, this username indicates someone adept at attracting girls. In a literal way, the first part “撩妹” means “flirting with girls” and “杠把子” here is used humorously to imply an outstanding ability or tool to do it. So altogether this refers to somebody very skilled in making advances towards young ladies.