Meaning of ふたり in Japanese

私たちは２人とも同じクラスです。
We are both in the same class.

この食事は二人分ある。
This meal is adequate for two.

じゃあ２人乗りを許してやるからお前漕げ、俺が荷台に乗るから。
Well then I'll allow two on a bike, but you peddle. Because I'll be sitting on the luggage platform.

その家で彼女は赤ん坊と二人きりだった。
She was alone with her baby in the house.

２人っきりでデート・・もとい、ＯＦＦ会だと思ったけど、そこまで甘くもないよな。
So I thought my date, er rather, offline-meeting was going to be just me and her but things aren't that easy.