How can I tell if my baby boy Bongo is just playing or pissed?

[Fbjdd]

Hi all,
Bongo is 10 weeks old and our Pug Louie is 7 months old. They play a lot together and play fight a lot Louie just grunts, chases mouth and playfully bite each other but Bongo does his little puppy barks and growls when there playing and mouthing each other the y bite on each others joules and lips both there tail are up and it looks like there playing. It's hard to tell because there tails don't really wag just to sort lol.
it doesn't seem like anger it seems like there playing but it's hard to tell does anyone have this kind of predicament?

 

[Watson]

it is puppy play, that's how they socialize and establish dominance

 

[JAKEISGREAT]

Definitely!! Puppies! Enjoy it..soon Bongo will be a Big

 

[Cooper11]

Yep puppy play! If you go to photo and videos forum I have some videos of my bullies playing! It almost seems like your at a dog fight at some points. I usually just let them go at it cuz they will stop on their own. If I think they are both getting a little carried away and big yell HEY!!! they both stop and act like nothing was going on and will wait 10 seconds and start playing again! Your little guys is only 10 weeks so it is for sure all play!!!! You pug will love having a wrestling buddy!