Is it necessary to use 2 condoms if you have a thick and long penis? and my girlfriend doesn't want to use the contraceptive pill?

Interesting Question: Using double condoms is a a rare thing in my medical experience. If you are so large you need 2 to guarantee integrity of the condom, perhaps this is an answer. Are you sure you have tried all of the "largest" & most durable condoms? You & a condom & her with the use of foam, film, suppositories or sponge may be a better alternative. I think the two of you need to have a long talk! get help?

Other options: If one's experience has shown that utilizing one condom has resulted in tears (even small ones), then it would appear a reasonable consideration. Other options which may be more practical include your girlfriend utilizing a contraceptive sponge, spermicide, diaphragm, and/or iud. The correct choice would require consultation with her gyn doctor.