Husband contacted his ex-girlfriend. He was sneaking around behind my back when he contacted me, but his ex-girlfriend was very liberal. Is he a playboy?

See how it goes. Preventive measures are necessary. You can talk to him about the necessity of sneaking around, because after all, he still cares about you. Don't listen to others. Reality is not a novel. Normal people will consider whether it will make you jealous, so you'd better communicate and strictly control the number and time of conversations between him and his ex-girlfriend.