Well, they met after an event at the Royal Albert Hall in London. They spent a whole night talking together. It was said they were left alone together in a hotel room, and when the other three Beatles returned, they found them simply talking about the favorite food. That was in 1963.
And yeah, a womanizer as Paul obviously cheated on Jane, repeatedly. Paul was constantly on tour between 63-66 and Jane stayed in London practically all the time. Then, things were the opposite: Jane started touring with a theatre company by 1966 and this time it was her who was away from London. So it was during this time that he saw other women, for example, Maggie McGivern. Paul met Maggie in 1966, while she was a nanny for Marianne Faithfull’s son. They started dating almost immediately and this lasted for two years. Jane never knew of this. In fact, Paul and Maggie broke up because he married Linda. Even when she didn’t know of Maggie, Jane knew that Paul wasn’t always loyal to her only, but remained quiet about this.
However, after Paul proposed to her, she thought things would change, now that they had formalized their relationship and were ready for marriage. But later in 1968, after a tour, Jane arrived without announcement to Paul’s house in Cavendish Avenue, only to find him in bed with another woman, Francie Schwartz. A few days later, Jane broke her engagement to Paul publicly on July 20, 1968.