My girl has been in season but it is a week now that she finished but one of my boys is still desperately trying to mate her. I know she has finshed as it is now over 4 weeks and my other male is no longer interested in her at all. However the younger male is just follwoing her round trying to mate her. he  is a lot smaller than her so is is just hanging on to her hind leg and not getting amywhere near mating her but  he is working him self up into a state so I am still having to keep them separated. The girl is not helping as she loves him so she is not telling him to leave her alone and is just letting him carry on. How can I persuade him to give up? she has had a bath and I have sprayed her with cologne to get rid of any smell.

try putting vanilla extract on her and his chest, I use it to mask the smell when my girls were in season and keep the boys from getting too worked up, only problem is I am sick of the smell by the time the season was over

Have you checked her anal glands? Full glands often seem to confuse dogs!

I don't think it is an issue about what she smells like as my other boy is taking no notice of her at all and he is the one who gets most frantic when a bitch is ready. I did try the vanilla essence suggested by Rodach but it didn't make any difference. I think he is just being an idiot. It would help if she told him off but she wont. She just stands there with him attached to her leg and will even flag. Her bits are shrinking and there is no discharge so she has definitely finished. I think she is being a bit of a floozy too.

Unless you have had her progesterone tested and know when she ovulated then i wouldnt be 100% sure she has finished, Of course she may just be a trollop but its not worth the risk.