Travel Trailer Brake light wiring

Hello,

I was working on replacing one of the brake lights on my travel trailer. I unscrewed my old brake light and thought I would use one of these butt splice connectors for connecting my lights but then I realized that these won't work since some of the current connections have three wires. I wasn't sure what the best connectors are for connecting three wires? I was thinking I could use wire nuts with electrical tape but that probably wasn't a good way. Should I use the T-Tap wire connectors like this since this is what was there previously?

Then I had to remove some white foam from the wires before I could get to the connectors. Once I get the wiring completed should I probably spray some of that foam back in there to make it more water proof? If so should I use something like this?

Any help would be much appreciated.

Thanks