That is how my baby bully and Boston were. Belly just wanted to play all the time and Gunner (13 years old) was so used to Cass who only played sporadically then wanted to nap all day. He was very snappy with her and hated her being close to him. He'd snarl his lip at her all the time. The trainer I talked to said to let him do it so the puppy learned her place in the pack. It took some time ( 2-3 weeks) and they actually lay close now and I'm not worried all the time he will try and bite her face off!
I wouldn't say they are pals just yet, but we're working on it. Give them time to get used to each other and I bet in time they will tolerate each other if not be buds!