RES turtles fighting

Question
I found a male RES turtle on the road.  I took him to a vet and he gave him some medicine incase he had parasites as I want to keep him.  I have a female RES that I have had for about 6 years and she is very healthy.  My female is about 10" and she is in an outdoor pond, the new male is about 5-6"After waiting about 48 hours after giving the male the medicine I tried to introduce him to my female in the pond.  They were very curious of each other but began fighting.  I took the male out and tried to reintroduce them together today, but they began fighting again. I tried to separate them, but they kept finding each other and fighting.  Is this normal?  In the past I have introduced other captive males to her and had no problem at all, but unfortunately my two males have had unfortunate accidents and died.   Will they eventually get used to each other with short supervised exposure to each other or should I just go ahead and release him back into the wild?  There is a nice creek behind my house.


Answer
In the wild they really have no human type manors/. You really should not breed them Is keeping them apart out of the question?
Id recommed releasing him as he just may not be able to be held as a captive turtle. He could get depressed and die. If you are wanting another turtle try a rescue


I do apologioze for the delay, I am a mom of 6 and 2 are special needs. My special needs daughter fell on my computer and broke the screen.
She went into a grandmal seizure and broke the screen.