I believe this is by Mary Calmes.  I was re-reading it on my tablet, which glitched, and removed the book completely.  I can't remember the title even though I've cruised through her books.  Here is the synopsis (and I apologise, I can't remember names to save my life):

Main Character (MC) has an older brother in law enforcement who has a real hound dog as a new partner (NP).  First time, MC and NP meet, NP wants to have sex in a car and MC, while amused and attracted, turns him down.  They run into each off and on for years but don't really get along that well.

In the meantime, MC was seeing (living with?) a doctor (Dr).  They've split up, in part, because Dr got a woman pregnant while away at a symposium.  Dr wants to get back together.

Somehow NP and MC meet up again and NP is trying to convince MC that MC is the man for him, now that he knows Dr is out of the way.  While that is happening, someone tries to kill Baby Mama (Mama).  It works out that MC, NP, Dr and Mama are all going back to Dr's home town on East Coast for protection.  Dr and Mama are supposed to be an engaged couple while MC and NP are supposed to be a couple.  Dr is still trying to get NP back.

At one point, Mama is kidnapped and MC finds her and attempts to save her while waiting on NP to find them both.

Does this ring a bell with anyone?  

I can't help with the book you are seeking but wanted to thank you for the name of an author.  I just read one of her books yesterday after you mentioned Mary Calmes and I really enjoyed her romance 'No quick fix"  Thanks for leading me to a new author. 

I'm happy one of us got something out of this, Susan!

I appreciate everyone who has looked.  

Found it!  It's called Floodgates by Mary Calmes!

Just finished Calmes Marshal series was really a good one. Mix of police work , mystery and romance.