Traveling to Uk as US citizen
So I am a US citizen and I have booked a flight going to London, I have a best-friend/old american roommate there and also a french boyfriend in school. I will be leaving LA on May 12th for my 3 in a half month trip, I am only planning on staying in London till the end of June... then I will be going to Paris which is where my boyfriend is originally from. We will be staying in his moms old flat for two weeks or so and seeing the Strokes concert . After all of this we have booked a Hotel in Spain to spend the rest of July and some of August. I will then go back to Paris where I will fly to New York for my Birthday. My question is I know how customs can be and I am self employed, I cut hair for a living... and i rent a back house from a friend.. how can I prove to customs that I am not intending on overstaying.
Also if my boyfriend will be paying for most of the trip what should i tell them as proof of funds.
Should I use my mothers bank statement to show she will help as well.
Should I be worried if I have addresses of where I am staying with american girlfriend who got married there, and Strokes tickets in Paris, and hotel reservation under my boyfriends name.... what do I do
Need advice please help . I leave soon