Bottlefeeding and nipple question?

[tilly2321]

Hello! My baby seems to do best with the playtex nurser latex nipple. I can't seem to figure out how to work the bottles though. THe bag gets all scrunched when I slide up the air using the slide up burper or even when I use the kind with the bag and just manually push the air out. Can anyone give me any recommendations of what I am doing wrong. ALso, does anyone know of any other bottles that this nipple would fit into or similar ones?
Thanks!
Elaine

[pearl]

I don't think you are doing anything wrong. The bags get scrunched up because you are pushing the air out.