A teacher who sent lewd emails referring to a pupil's breasts and telling her "condoms are boring" has been banned from the profession.
David Fishwick, 25, also told the teenager "I'd love to see you drunk" at St Christopher's CE High School in Accrington, Lancashire.
The girl had pleaded with him to stop, telling him: "I'm crying myself to sleep", a disciplinary panel heard.
The science teacher admitted unacceptable professional conduct
Sitting at a Teaching Regulation Agency hearing in Coventry, panel chairman Alan Meyrick said Mr Fishwick could not apply to teach again for five years.
The messages were sent over a month in early 2017, the panel heard.
Mr Fishwick referred to the girl as "my fave student of all time" and made repeated references to the size of her breasts, the hearing was told.
He wrote: "I know what girls are like. They think anything that's a B or C is small."
He also asked her for hugs, claimed he loved her and dreamed about her.
Another time, he said boys would "have to get past me before they can have you".
When he asked her about her sexual experience, the girl replied with: "Sir, [that's] not a question you should ask a pupil", the panel heard.
The messages and the girl's replies filled 270 pages of evidence at the hearing.
Although Mr Fishwick admitted misconduct, he denied the messages were "sexually motivated".
The panel disagreed and found that they were.
Mr Fishwick apologised with "wholehearted contrition and remorse" for the "deep embarrassment and hurt" he had caused.
Chairman Mr Meyrick said: "Mr Fishwick had sent sexually motivated inappropriate messages to the pupil despite her repeated requests for the messages to cease."