popuštati

1. (+ dat.) to give in; to yield; to indulge
   Nemoj mu stalno popuštati, razmaziće se. — Don't keep giving in to him, he'll get spoiled.
   Vlada ne popušta pred pritiskom sindikata. — The government isn't yielding to union pressure.
2. (of pain, cold, wind) to ease; to subside; to let up
   Bol polako popušta posle tablete. — The pain is slowly easing after the pill.
   Vrućina ne popušta već dve nedelje. — The heat hasn't let up for two weeks.
3. to loosen; to come loose
   Šraf na vratima stalno popušta. — The screw on the door keeps coming loose.
4. (of price) to come down; to knock off
   Prodavac ne popušta ni dinar. — The seller won't knock off a single dinar.
5. (of performance, work) to slack off; to slip
   Sin je počeo da popušta u školi. — Our son has started slipping at school.

In the sense 'to give in to someone' it takes the dative: popuštati detetu.