My former partner will not accept that we will never get back together again.

When he picks up our daughters, he takes the opportunity to make suggestive remarks or to tell me he still loves me.

You need to make it clear that there is no chance of getting back together. Speak to him on the telephone when your daughters are not present (or write a letter/email). Say that your relationship is over and you want him to stop putting this emotional pressure on you. Stress that you still both love your daughters and the best thing for them is if you can both behave in a calm business-like way and that if he continues like this, he will have to pick up the girls from another family member or the local Child Contact Centre.