Wow, I think you are getting a really tough time on here @StarClouds
I honestly don't see the harm in you having a guy round in the evening, and even staying the night and leaving before the kids get up, that you have been getting to know for 6 months. Or even introducing them to him. Surely we introduce new friends to our children all the time?
If you have been getting to know each other and dating for 6 months then you are not strangers to one another.
I am pretty sure you are capable of making sure you keep your kids safe around this guy until you are 100% sure you can trust him.
No-one with kids in the house are going to take any silly chances in that 'getting to know you' first year and put the kids at risk but surely having someone round for dinner while the kids sleep is pretty safe.
What do people think is going to happen?
How are you supposed to move a relationship on to the next level if you can't spend evenings together in one another's company?
Not all men are dangerous sexual predators who will prey on your kids and only date a single mom to get close to the kids. In fact, the majority are not.
As long as you air on the side of caution with the kids then all should be fine.