I feel Capaccino MrsJREwing is on to something there.
I also feel someday is probably correct and letting you know what this is all leading up to: he is engineering a move in to your home (feet under the table and all that)
Don't answer the following out loud here if you don't feel it, however I'll ask the questions never the less:
Do you own your own home?
Do you have a good income? Maintenance? Independent income?
Is he expecting you to accept "a couple of hundred pounds a month" to live at yours - as opposed to having to pay full rent/bills at his own home?
Will you be providing full housekeeping services for him?
Are you generally known as a "nice" woman who'll generally stay at home whilst letting her "man" have free rein to "go out and do his own thing without complaint"?
Do you stay at home a lot because you have a young daughter?
Will he be childminding your daughter for you, alone, at any time whilst you work/shop/socialise? If no, why not? Does your love for him include trusting him to bring no harm to your daughter? (How long have you known him)
How prepared are to to co-parent - as a step parent - with a woman who wants to "kill you"?
Will you consider official family mediation for the three of you?
When will their children be staying with you? Weekdays? Weekends? One week at her house? One week at your house?
If you were not on the scene, what would his plans be with regards his housing/job/income? Would he simply stay at his mothers until another suitable woman came along?
Why could he not live separately from you?
It is your life - however of more consideration, it is your child's life.
Do take time to consider these questions very carefully.