  We report detailed, long term near-infrared (NIR) light curves of GRS
1915+105 in 2007-2008, covering its long "soft state" for the first time. From
our NIR monitoring and the X-ray data of the All Sky Monitor (ASM) onboard
Rossi X-ray Timing Explorer (RXTE), we discovered that the NIR flux dropped by
> 1 mag during short X-ray flares with a time-scale of days. With the
termination of the soft state, the H-Ks color reddened and the anti-correlation
pattern was broken. The observed H-Ks color variation suggests that the
dominant NIR source was an accretion disk during the soft state. The short
X-ray flares during the soft state were associated with spectral hardening in
X-rays and increasing radio emission indicating jet ejection. The temporal NIR
fading during the X-ray flares, hence, implies a sudden decrease of the
contribution of the accretion disk when the jet is ejected.
