Sexing bolivian rams

[Fishymom64]

Hello everyone! I have a 40 gallon tank that has been running for about 6 months. I have one bolivian ram I got about 4-5 months ago that I believe is male. (He lifts his black part of his top fin a lot and chases other fish away occasionally) Anyway, a few days ago I went to the store and got what is hopefully a female bolivian ram in the hopes they would get along. I made sure they had a good return policy and have been watching them carefully. I have seen the new one eat and it usually hangs near the back of the tank around the plants. I am a little concerned just because the what I believe to be male bolivian ram is significantly larger. The two seem to be mostly ignoring each other except for when the male (maybe) chases the other around some.
So my question is, should I keep the new one I got or will there be future problems and I need a little help on determine the sex’s of the fish. Thank you and I’m open to any suggestions!
The first two photos is the one I think is male that I have had for a few months
The other is what I hope is the female (but might be a young male)
Thanks!

 

[CTYankee79]

I’m not an expert but the first one is almost definitely a male...bump on head, black dorsal, pointed analfin. The second one is hard to tell for me, perhaps Feohw can confirm.
My limited experience with Bolivian Rams—I bought two, one which appeared to be a male and a smaller one appeared to be a female. Turns out the female was definitely a male. The bigger “male” we were never quite certain what sex. At first they hung out together, then they each claimed a side of the tank. Slowly the smaller male took over the entire tank, and ended up bullying the bigger one to death. It happened so quickly I didn’t even have time to rehome (or even think I needed to until it was too late). Everybody has different experiences with them.
Your male does look a little stressed, but mine does look like that sometimes as well and then is fine an hour later.

 

[Feohw]

The second one is hard to tell for me, perhaps Feohw can confirm.

Looks to be a female.

 

[Fishymom64]

Ok thanks everyone! They seem to be ignoring each other as of now and the new smaller one is a bit more at home. I’ll continue to watch them but thanks for your help.