Pull-Ups and chafing?

Cytina

We recently started putting DS1 in Huggies Pull-Ups.  We've always used Huggies diapers with no problem.  But just yesterday, I saw he has very badly chafed, red inner thighs!  I *think* it might be b/c the Pull-Ups are a little big and the sagging in the crotch area rubs against his thighs?  I bought them in the smallest size, 2T/3T.  DS1 is so skinny though!  Anyone else have a same/similar problem?

sar17

YES, it was terrible, we switched to pampers. they are softer/smaller and have specific sizes