Hey Tara, as someone speaking from experience, I'd say that people's attitude are generally welcoming. It doesn't make a difference to the younger generation ie people under 40. You can walk around freely holding hands with your girlfriend, kiss in public etc. The LGBT scene in Singapore is also more active now although it is not yet on par with the western countries.
There will always be homophobes around but they generally won't create problems with you. However, it's good to avoid PDA on public transports in general espcially if there are elderly around. This is also the case for hetero couples but same sex PDA is less tolerated IMO.
If you're not planning on buying a house here (that's another can of worms to open), living in Singapore should be fine