Why are ppl surprised at his nature for? coz to me it was obvious, he desired Anjali and wanted her but wasnt falling for her, so in that sense i didnt find it surprising that he stooped that low, he doesnt have respect for anyone, i would have atleast thought that living with Anjali he would have noticed and understand that Anjali isnt that kind of woman to do things that what Soham wanted her to do, or isnt even that kind of a woman.
Remember he isnt exactly Mr Goody is he from the start and you have seen the way he looks at other women, and also his weakness is women