If you're interested in someone romantically, you might flirt with them, which means to chat them up or tease them in a playful way.

Flirting is an indirect and fun way to let your crush know you're interested, like a seductive line or a few coy words. Or if there's a girl you've had your eye on, you might make a point of walking by her desk and saying hello every morning. But even if you don't have a love interest, you can still flirt. Driving carelessly is flirting with disaster: it's almost like you're toying with the idea of getting into an accident.

Definitions of flirt

v talk or behave amorously, without serious intentions

“My husband never flirts with other women”
butterfly, chat up, coquet, coquette, dally, mash, philander, romance
engage in amorous play
act seductively with (someone)
Type of:
speak, talk
exchange thoughts; talk with

v behave carelessly or indifferently

dally, play, toy
dally, play, trifle
consider not very seriously
Type of:
act, move
perform an action, or work out or perform (an action)

n a seductive woman who uses her sex appeal to exploit men

coquette, minx, tease, vamp, vamper
Type of:
adult female, woman
an adult female person (as opposed to a man)

n playful behavior intended to arouse sexual interest

coquetry, dalliance, flirtation, flirting, toying
Type of:
caper, frolic, gambol, play, romp
gay or light-hearted recreational activity for diversion or amusement